Method of manufacturing a multi-layer wiring board using a metal member having a rough surface

ABSTRACT

Methods are provided for manufacturing a wiring circuit element or wiring board in which a set of rough wiring patterns are formed by selectively etching a metal layer of a patternable member which includes a carrier layer having a rough surface and a thin rough-surfaced etch stop layer between the carrier layer and the metal layer. The etch stop layer and wiring patterns are joined to an insulating layer such that the wiring patterns adhere to the insulating layer and the insulating layer acquires a rough surface. Thereafter, the carrier layer and the etch stop layer are removed, after which openings are formed in the insulating layer in contact with at least some of the wiring patterns. A layer of metal is electrolessly plated onto the rough major surface of the insulating layer, and then a conductive wiring pattern is selectively electroplated over the electrolessly plated layer to form plated openings that interconnect at least some of the wiring patterns.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 11/585,064, filed Oct. 23, 2006, which is a continuation of U.S. patent application Ser. No. 11/356,672, filed Feb. 17, 2006, which is based upon and claims the benefit of priority from Japanese Patent Application No. 2005-43784, filed Feb. 21, 2005, the disclosures of which are hereby incorporated by reference herein.

BACKGROUND OF THE INVENTION

Wiring boards typically have a wiring layer formed on the surface of an insulating substrate such that the thickness of the wiring layer protrudes above the surface of the insulating substrate. In boards which have high wiring pattern densities, such structures are prone to short-circuiting problems, particularly where contacts to the wiring layers are formed.

Wiring boards are known in which the surfaces of wiring patterns themselves are embedded in the insulating material at the surface of the substrate so as to be coplanar (located at the same plane) with the surface of the insulating material. Examples of such wiring board structures are described in Japanese Examined Patent Application Publication H 6-21619.

FIGS. 4(A) through 4(G) show one example of the production steps in a method of manufacturing a wiring board having such structure. In a typical method, a transfer technique is used to make a wiring board in which exposed surfaces of the insulating material and the wiring layer embedded therein are coplanar.

(A) As shown in FIG. 4(A), a three-layer metal member is prepared by providing a nickel layer b as an etch stop layer overlying a copper carrier layer a, and a copper layer c overlying the surface of the nickel layer b as a layer from which wiring patterns will be formed.

(B) Next, as shown in FIG. 4(B), by selectively etching the copper layer c, wiring layers d, d, are formed to provide a wiring member “e”. In the etching process, the nickel layer b prevents the copper carrier layer a from being etched.

(C) Two wiring members e as shown in FIG. 4(B) are prepared and disposed in opposition to each other such that the wiring layers d, d face each other. The wiring members e are pressed together with a glass fiber epoxy resin member f disposed between them to form a combined structure as shown in FIG. 4(C).

(D) The copper carrier layer a and the nickel layer b are no longer needed and are then removed, as shown in FIG. 4(D). In so doing, a wiring board is completed in which the wiring layers d, d, . . . have exposed surfaces d1 which are coplanar with the exposed surfaces f1 of the insulating material f.

(E) Next, as shown in FIG. 4(E), through holes g are formed where needed to provide interlayer connections between the wiring patterns on the top and bottom surfaces of the insulating material.

(F) Next, as shown in FIG. 4(F), a thin metallic film h is formed by electrolessly plating the entire exposed surface of the wiring board, and subsequently a photoresist layer i is formed and patterned as a mask for forming the through holes.

Having done so, using this photoresist layer i as a mask for electroplating, copper layer j is deposited electrolytically onto exposed surfaces of the electrolessly formed film to form plated through holes 24. FIG. 4(F) shows the condition after this copper layer j is formed.

(G) Next, this photoresist layer is removed and the thin layer h formed by electroless plating is removed to complete the wiring board (FIG. 4(G)) which includes a copper layer j covering through holes g to connect the wiring patterns exposed at opposite surfaces of the wiring board. Next, although not indicated in the drawings, the electrodes of electronic parts are connected by means of solder, etc. to the copper layer j, etc., in areas of the wiring board not covered by a selectively-formed solder resist.

However, the background technology shown in FIGS. 4(A) through 4(G) has the following problems:

First, it is difficult to form the copper layer j by the additive process shown in FIGS. 4( a) through 4(G) because of poor connection, poor bonding, and peeling of the copper layer j from the through holes due to the process of electrolytic plating used to form copper layer j and the electroless plating process which is assumed to be unavoidable for forming the copper underlayer h.

Second, a selective electrolytic etching process used to form the resist layer i interferes with the additive process of forming the copper layer j, making copper layer j prone to poor connection, poor bonding, and peeling.

Third, upon completing the steps outlined in FIG. 4(G), it is necessary to selectively form a solder resist layer overlying wiring layers d.

These problems, in large part, are due to the exposed surfaces f1 of the glass fiber epoxy resin member f of the insulating material being smooth and failing to adequately grip the electroless and electrolytic metal layers disposed thereon.

SUMMARY OF THE INVENTION

According to various embodiments of the invention described herein, methods are provided herein for manufacturing a wiring circuit element or wiring board. In a method in accordance with one embodiment of the invention, a patternable member is provided which includes a carrier layer having a rough surface, a thin etch stop layer overlying the rough surface and a metal layer overlying the etch stop layer. As a result, corresponding surfaces of the etch stop layer and the metal layer overlying and adjacent to the rough surface of the carrier layer are rough. The metal layer is etched selectively to a material of the etch stop layer to form a plurality of wiring patterns and to expose the rough surface of the etch stop layer between the wiring patterns. An insulating layer is joined to the wiring patterns and to the exposed rough surface of the etch stop layer. Thereafter, the carrier layer and the etch stop layer are removed from the insulating layer to expose the wiring patterns and expose a rough major surface of the insulating layer between the wiring patterns. Openings are then formed in the insulating layer in contact with at least some of the wiring patterns. A layer of metal is electrolessly plated onto the rough major surface of the insulating layer and within the openings in the insulating layer. Thereafter, a conductive wiring pattern is selectively electrolytically plated over the electrolessly plated layer and within the openings to form plated openings which conductively interconnect at least some of the wiring patterns. Portions of the electrolessly plated layer exposed by the conductive wiring pattern can then be removed.

In accordance with a particular embodiment of the invention, at least two patternable members are used such that first and second exposed surfaces of the insulating layer are joined to the wiring patterns and exposed rough surfaces of the etch stop layers. In such embodiment, the step of forming openings in the insulating layer includes forming through holes extending from the first surface through the insulating layer to the second surface. In addition, the step of selectively electrolytically plating a conductive wiring pattern conductively interconnects wiring patterns exposed at the first surface with wiring patterns exposed at the second surface of the insulating layer.

In accordance with one or more embodiments of the invention, the etch stop layer includes a metal which is not attacked by an etchant which attacks a metal included in the metal layer overlying the etch stop layer.

Preferably, the etch stop layer consists essentially of nickel and the carrier layer and the metal layer overlying the etch stop layer each consists essentially of copper.

In a particular embodiment of the invention, the patternable member is formed by forming the thin etch stop layer over the rough surface of the carrier layer and forming a second metal layer over the etch stop layer. Preferably, the carrier layer includes a metal.

The roughness of the exposed surface of the carrier layer in contact with the etch stop layer is such that it has unevenness of between about 0.1 micron and about 10 microns.

Preferably, a solder mask is formed to overlie surfaces of the wiring circuit element in such manner that the solder mask exposes the electrolytically plated conductive wiring patterns.

In accordance with one or more preferred aspects of the invention, the wiring patterns are embedded in the insulating layer such that the rough major surface of the insulating layer is co-planar with exposed major surfaces of the wiring patterns.

In accordance with another embodiment of the invention, a method of manufacturing a multi-layer wiring circuit element is provided. In such method, a first patternable member and a second patternable member are provided in which each of the first and second patternable members includes a carrier layer having a rough surface, a thin etch stop layer overlying the rough surface and a metal layer overlying the etch stop layer. In this way, corresponding surfaces of the etch stop layer and the metal layer overlying and adjacent to the rough surfaces of the carrier layer are rough. The metal layers of the first and second patternable members are etched selective to a material of the etch stop layer to form first wiring patterns overlying the etch stop layer of the first patternable member and form second wiring patterns overlying the etch stop layer of the second patternable member and expose the rough surfaces of the etch stop layers in areas exposed by the first or second wiring patterns. Thereafter, the first and second insulating layers are joined to the wiring patterns and exposed etch stop layers of the first and second patternable members, respectively. An interconnection element including at least a third insulating layer is subsequently joined to the first and second insulating layers, the interconnection element having a plurality of interconnect wiring patterns extending in one or more directions parallel to an exposed surface of the third insulating layer. Thereafter, the carrier layers and the etch stop layers are removed to expose the wiring patterns joined to the first and second insulating layers and rough major surfaces of the first and second insulating layers between the wiring patterns. Through holes are formed which extend through the first, second and third insulating layers, the through holes contacting at least some of the wiring patterns. Subsequently, a layer of metal is electrolessly plated onto the rough major surfaces of the first and second insulating layers and within the through holes. Thereafter, conductive wiring patterns are selectively electrolytically plated over the electrolessly plated layers and within the through holes. Portions of the electrolessly plated layers exposed between the electrolytically plated conductive wiring patterns are removed.

In a preferred embodiment of the invention, blind openings are formed which extend through at least one of the first and second insulating layers to the interconnect wiring patterns. In such case, the step of selectively electrolytically plating conductive wiring patterns includes electrolytically plating the conductive wiring patterns in the blind openings to connect the interconnect wiring patterns with at least some of the first or second wiring patterns.

Preferably, the interconnect wiring patterns of the interconnection element are disposed in a plurality of wiring layers separated by respective insulating layers, and the interconnection element further includes plated through holes which conductively interconnect the plurality of wiring layers of the interconnection element.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1(A) through 1(M) are cross sectional views illustrating a method of manufacturing a wiring board in accordance with a first embodiment of the invention.

FIGS. 2(A) through 2(H) are cross sectional views illustrating a method of manufacturing a wiring board in accordance with a second embodiment of the invention.

FIG. 3 is a cross sectional view illustrating a wiring board in accordance with the invention.

FIGS. 4(A) through 4(G) are cross sectional views illustrating a method of manufacturing a wiring board according to the prior art.

DETAILED DESCRIPTION

In the embodiments of the invention described below, one of the major surfaces of a carrier layer which serves as a member for the manufacture of a circuit board is a rough surface. This rough surface is transferred to a metal etch stop layer and, in turn, to a metal wiring layer formed on that rough surface. The rough surface is then transferred to insulating material which forms a base of the board. The insulating material which forms the base of the wiring board preferably includes epoxy resin in which glass fibers are embedded. After the metal wiring layer is patterned, the metal wiring layer and the insulating material retain the rough surface when the carrier layer is removed.

A preferred method of interconnecting wiring layers of the wiring board is to form through holes and then line the through holes by electroless plating of copper or other metal. A resist layer is then formed and copper or other metal is then selectively deposited by electrolytic plating. Preferably a dry resist layer is used as this resist layer.

The embodiments of the invention provided herein are described with reference to the drawings.

FIGS. 1(A) through 1(M) are cross sectional views showing the production steps in manufacturing a wiring board according to a first embodiment of this invention.

(A) As shown in FIG. 1(A), a carrier layer 2 is prepared which preferably includes or consists essentially of copper and has a thickness of several microns to several hundred microns. At least one of the major surfaces of this carrier layer 2 has an average roughness of approximately 0.1 microns to about 10 microns measured by unevenness in the surface. Commercially available copper foil exists which has approximately this degree of roughness on at least one of its major surfaces. It is also acceptable to use a copper foil or other metal foil as the metal carrier layer 2 which has unevenness on both of its surfaces.

(B) Next, as shown in FIG. 1(A), an etch stop layer 6 including or consisting essentially of nickel, for example, and preferably having a thickness of under 1.0 microns is formed on the rough major surface 4 of the carrier layer 2.

Like the surface 4 of the carrier layer, the surface of the etch stop layer 6 is also rough. This is because the etch stop layer 6 is thin, preferably under 1.0 microns and follows the roughness of the uneven major surface 4 of the carrier layer 2.

(C) Next, as shown in FIG. 1(C), a metal layer 8, preferably consisting essentially of copper and having a thickness of several microns to several hundred microns is formed on the surface of the etch stop layer 6 to complete a member 10 for use in manufacturing a wiring board. The metal layer 8 will be subsequently patterned into wiring patterns of the wiring board.

(D) Next, as shown in FIG. 1(D), wiring patterns 12, 12, . . . are formed by selectively etching the metal layer 8. The rough surface of the etch stop layer 6 is exposed by this etching process in areas between the wiring patterns 12, 12. The member obtained after performing this step (D) is 10 a.

(E) Next, as shown in FIG. 1 (E), the two members 10 a, 10 a are disposed opposite each other so that the surfaces on which wiring patterns 12, 12, . . . are formed face each other, with a layer of insulating material 14 disposed between them, the layer 14 preferably including glass fiber and epoxy resin. The members 10 a and insulating material 14 are joined by heat and pressure.

At this time, the rough surfaces of the metal members 10 a are transferred to the surfaces 16 of the insulating material 14 to make them rough as well, except where the insulating material contacts the wiring patterns 12, 12 . . . . The rough surfaces of the etch stop layers 6 are transferred to the major surfaces 16 of the insulating material 14.

Although in the embodiment illustrated in FIGS. 1(A) through 1(E) wiring patterns 12, 12, . . . are formed on both major surfaces of the insulating material 14, in other embodiments wiring patterns 12, 12, . . . can be provided at only one major surface of the insulating material 14.

(F) Next, as shown in FIG. (F), the carrier layer 2 and the etch stop layer 6 are removed because they are no longer needed. In so doing, a wiring board is completed in which the exposed surfaces 15 of the wiring patterns 12, 12, . . . are coplanar with the exposed major surfaces 16 of the insulating material 14 and both the exposed surfaces 15 of the wiring patterns and the exposed major surfaces of the insulating material are rough surfaces.

(G) Next, as shown in FIG. 1(G), through holes 18 are formed which cut through or adjoin the wiring patterns 12 on both sides of the insulating material. The through holes, after further processing, facilitate interlayer connections between the wiring patterns 12.

(H) Next, as shown in FIG. 1 (H), a thin metal layer 20, preferably including or consisting essentially of copper, is formed by electroless plating over the entire surfaces of the wiring board including within through holes 18 and over major surfaces 16 of the insulating material and exposed surfaces 15 of the wiring patterns. The copper layer 20 preferably is thin, from about 0.02 microns up to several microns in thickness. Since the copper layer 20 is formed on the rough surface 16 of the insulating material 14, it avoids problems of poor bonding and a tendency to peel that plague the electroless copper layer of the wiring bond formed according to the prior art method (FIGS. 4(A) through 4(G)).

(I) Next, as shown in FIG. 1(I), a resist layer 22 is selectively formed, e.g., either by selective deposition or subtractive patterning, as a mask for further processing of the metal layer 20 overlying through holes 18. The selective formation of this resist mask 22 preferably is performed by applying a photoresist that is a dry film over the entire surface of the wiring board 10 a, exposing the resist to light and developing it. Since the resist layer 22 is formed on the rough-surfaced copper layer 20, it bonds more strongly to the insulating material 14 and is better able to avoid the problems of the prior art of poor bonding and the tendency to peel.

(J) Next, as shown in FIG. 1(J), a metal layer, e.g., copper layer 24 is formed by electrolytic plating in the through holes, with the resist layer 22 functioning as the mask.

(K) Next, as shown in FIG. 1(K), the resist layer 22 is removed.

(L) Next, as shown in FIG. 1(L), the copper layer 20 is removed.

(M) Next, as shown in FIG. 1(M), a solder resist layer 26 is selectively formed.

This solder resist layer 26 is formed on the rough surface of the insulating material 14. Therefore, the solder resist layer strongly adheres to the underlying insulating material 14, avoiding the above-described problems of poor bonding and the tendency to peel.

FIGS. 2(A) through (M) are cross sectional views showing production steps in a method of manufacturing a wiring board in accordance with a second embodiment of the invention.

(A) First, a member for the manufacture of a wiring board 10 is prepared in a manner as described above with reference to FIG. 1(C), and wiring patterns 12, 12, . . . are formed by selectively etching the metal layer 8, to form the wiring board member 10 a having a carrier layer 2 and etch stop layer 6 having an exposed rough-surface as shown in FIG. 2(A).

(B) Next, as shown in FIG. 2(B), an insulating layer 40 consisting, for example of resin, is bonded to the rough surface of the member 10 a upon which the wiring patterns 12, 12, . . . are formed.

(C) As shown in FIG. 2(C), a base is prepared that includes metal layers 44, 44 on both sides of a layer of insulating material 42. Layer 42 preferably includes or consists essentially of a resin, for example.

(D) Next, referring to FIG. 2(D), two members 10 a, 10 a are bonded to the metal layers 44, 44 on both sides of the base.

Next, the carrier layers 2,2 of the members 10 a, 10 a on both sides are removed, and the etch stop layers 6, 6 are removed, leaving rough surfaces 15 of the wiring patterns and rough surfaces 41 of the insulating material 40 exposed.

After that, blind openings 46, 46, serving as the interlayer connection means, and through holes 48 are formed, to provide the structure shown in FIG. 2(D).

Next, referring to FIG. 2(E), a metal layer 50 of copper or the like is formed by electroless plating over the exposed surfaces. Subsequently, the through holes are selectively electrolytically plated with copper or other suitable metal at which time resist patterns 52, 52 serve as the required plating mask.

In such manner, plated through holes 54 and plated blind openings 56 provide interlayer connections between the wiring patterns 12 on each side of the insulating material 40. FIG. 2(E) shows the plated through holes 54 and plated blind openings 56 after they are formed.

(F) Next, as shown in FIG. 2(F), the resist layers 52, 52 are removed.

(G) Next, as shown in FIG. 2(G), the metal layer 50 that was formed by electroless plating is removed in exposed areas not covered by the electrolytically plated layer.

(H) Next, as shown in FIG. 2(H), a solder resist layer 58 is selectively formed to cover areas other than the plated through holes 54 and plated blind openings 56.

The embodiment shown in FIGS. 2(A) through 2(H) is configured to obtain a wiring board that is slightly different in structure from the embodiment shown in FIG. 1. However, by using the member 10 shown in FIG. 1(C) the technological effect of the embodiment that is shown in FIGS. 1(A) through 1(M) can be obtained.

FIG. 3 is a cross sectional view showing a wiring board according to a third embodiment of the invention in which a plated through hole 55 conductively interconnects internal wiring pattern layers 60 and 62 but does not conductively interconnect those layers to the outermost wiring patterns 12. Internal wiring pattern layers 60 or 62 are conductively interconnected to another plated through hole 54 which provides conductive interconnection to outermost wiring patterns 12. Plated blind vias 56 provide further interconnection between wiring patterns 12 and wiring pattern layers 60.

Thus, this embodiment of the invention facilitates manufacture of a more multi-layered structure, a greater diversity of through-hole shapes, and can facilitate the manufacture of wiring boards with a variety of structures.

Layers including copper or the like used to plate the through holes are formed using electrolytic plating of copper or the like in this particular embodiment, but the invention is not limited to this, and can be formed using, for example, conductive fillers.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. 

1. A method of manufacturing a wiring circuit element comprising the steps of: providing a patternable member including a carrier layer having a rough surface, a thin etch stop layer overlying the rough surface and a metal layer overlying the etch stop layer such that corresponding surfaces of the etch stop layer and the metal layer overlying and adjacent to the rough surface of the carrier layer are rough; etching the metal layer selectively to a material of the etch stop layer to form a plurality of wiring patterns and to expose the rough surface of the etch stop layer between the wiring patterns; joining an insulating layer to the wiring patterns and to the exposed rough surface of the etch stop layer; thereafter removing the carrier layer and the etch stop layer from the insulating layer to expose the wiring patterns and expose a rough major surface of the insulating layer between the wiring patterns; forming openings in the insulating layer in contact with at least some of the wiring patterns; electrolessly plating a layer of metal onto the rough major surface of the insulating layer and within the openings in the insulating layer; selectively electrolytically plating a conductive wiring pattern over the electrolessly plated layer and within the openings to form plated openings which conductively interconnect at least some of the wiring patterns; and removing portions of the electrolessly plated layer exposed by the conductive wiring pattern.
 2. The method as claimed in claim 1, wherein exposed first and second opposite surfaces of the insulating layer are joined to the wiring patterns and exposed rough surfaces of the etch stop layers of at least two of the patternable members, the step of forming openings in the insulating layer includes forming through holes extending from the first surface through the insulating layer to the second surface, and the step of selectively electrolytically plating a conductive wiring pattern conductively interconnects wiring patterns exposed at the first surface with wiring patterns exposed at the second surface of the insulating layer.
 3. The method as claimed in claim 1, wherein the etch stop layer includes a metal which is not attacked by an etchant which attacks a metal included in the metal layer overlying the etch stop layer.
 4. The method as claimed in claim 3, wherein the etch stop layer consists essentially of nickel and the carrier layer and the metal layer overlying the etch stop layer consist essentially of copper.
 5. The method as claimed in claim 4, wherein the patternable member is formed by forming the thin etch stop layer over the rough surface of the carrier layer and forming a second metal layer over the etch stop layer.
 6. The method as claimed in 3, wherein the carrier layer includes a metal.
 7. The method as claimed in claim 1, wherein the exposed surface of the carrier layer in contact with the etch stop layer has unevenness of between about 0.1 micron and about 10 microns.
 8. The method as claimed in claim 5, further comprising forming a solder mask overlying surfaces of the wiring circuit element, the solder mask exposing the electrolytically plated conductive wiring patterns.
 9. The method as claimed in claim 1, wherein the wiring patterns are embedded in the insulating layer such that the rough major surface of the insulating layer is co-planar with major surfaces of the wiring patterns.
 10. A method of manufacturing a multi-layer wiring circuit element, comprising the steps of: providing a first patternable member and a second patternable member, each of the first and second patternable members including a carrier layer having a rough surface, a thin etch stop layer overlying the rough surface and a metal layer overlying the etch stop layer, such that corresponding surfaces of the etch stop layer and the metal layer overlying and adjacent to the rough surfaces of the carrier layer are rough; etching the metal layers of the first and second patternable members selective to a material of the etch stop layer to form first wiring patterns overlying the etch stop layer of the first patternable member and to form second wiring patterns overlying the etch stop layer of the second patternable member and to expose the rough surfaces of the etch stop layers in areas exposed by the first or second wiring patterns; joining first and second insulating layers to the wiring patterns and exposed etch stop layers of the first and second patternable members, respectively; joining an interconnection element including at least a third insulating layer to the first and second insulating layers, the interconnection element including a plurality of interconnect wiring patterns extending in one or more directions parallel to an exposed surface of the third insulating layer; thereafter removing the carrier layers and the etch stop layers to expose the wiring patterns joined to the first and second insulating layers and rough major surfaces of the first and second insulating layers between the wiring patterns; forming through holes extending through the first, second and third insulating layers, the through holes contacting at least some of the wiring patterns; electrolessly plating a layer of metal onto the rough major surfaces of the first and second insulating layers and within the through holes; selectively electrolytically plating conductive wiring patterns over the electrolessly plated layers and within the through holes; and removing portions of the electrolessly plated layers exposed between the electrolytically plated conductive wiring patterns.
 11. The method as claimed in claim 10, further comprising forming blind openings extending through at least one of the first and second insulating layers to the interconnect wiring patterns, wherein the step of selectively electrolytically plating conductive wiring patterns includes electrolytically plating the conductive wiring patterns in the blind openings to connect the interconnect wiring patterns with at least some of the first or second wiring patterns.
 12. The method as claimed in claim 10, wherein the interconnect wiring patterns of the interconnection element are disposed in a plurality of wiring layers separated by respective insulating layers, the interconnection element further including plated through holes conductively interconnecting the plurality of wiring layers of the interconnection element.
 13. The method as claimed in claim 12, further comprising forming a solder mask overlying surfaces of the multi-layer wiring element, the solder mask exposing the electrolytically plated conductive wiring patterns.
 14. The method as claimed in claim 10, wherein the etch stop layer of each patternable member consists essentially of nickel and the carrier layer and the metal layer overlying the etch stop layer consist essentially of copper.
 15. The method as claimed in claim 14, wherein each of the first and second patternable members is formed by forming a thin etch stop layer over the rough surface of the carrier layer and forming a second metal layer over the etch stop layer.
 16. The method as claimed in 13, wherein the carrier layer of each patternable member includes a metal.
 17. The method as claimed in claim 10, wherein the carrier layer of each patternable member has unevenness of between about 0.1 micron and about 10 microns. 